Abstract: A communication system having remotely controllable signal receiving means for automatically setting the receive function for a start-signal transmitted from a terminal device and for changing the receive function when the terminal device is changed. At start-up, a main processor reads start-signal type information for each of the terminal devices from a main memory. The line circuits associated with the respective terminal devices are then set with a start-signal receive function according to the start-signal type information. When a terminal device is added or changed, the start-signal receive function is changed by merely updating the start-signal type information stored in the main memory.